Temperature indicator switch



Oct. 24, 1950 A, T, MCCARY 2,526,679

' 'IQEMPERATURE INDICATOR SWITCH Filed March 19, 1947 2 Sheets-Sheet 1 Oct. 24, 1950 A. 1'. M cARY TEMPERATURE INDICATOR SWITCH Filed March 19, 1947 2 Sheets-Sheet 2 Patented Oct. 24, 1950 UNITED STATES PATENT OFFICE TEMPERATURE INDICATOR SWITCH Alva Tyree McCary, El Paso, Tex.

Application March 19, 1947, Serial No. 735,706

1 Claim. 1

This invention relates to a predetermined high or low temperature indicating means.

An object of this invention is to provide a temperature indicating means for mounting within a refrigerator or other place of use so that the user will be able to determine at a glance Whether the temperature of the air within the location of use is being maintained within a predetermined temperature range.

Another object of this invention is to provide, in combination with a refrigerator, a temperature indicating means which will indicate maintenance of minimum and maximum temperatures Within the refrigerator.

A further object of this invention is to provide a device of this kind which can be manually adjusted so that the signal elements may be brought into operation at any desired minimum and maximum temperature ranges.

A further object of this invention is to provide a device of this kind which is simple in construction and can be manufactured as a relatively small unit for mounting within the location of use, which has correlated therewith a pair of signal elements which, in one instance, may be remote from the refrigerator or other location of use. so that the user of the device will have a visible or audible indication as to whether the temperature of the air within the place of use is at a dangerously high or low temperature.

As referred to herein, it will be understood that the term refrigerator is intended to comprehend any and all other suitable locations of use, as for example, a sickroom, etc.

With the above and other objects in view, my invention consists in the arrangement, combination and details of construction disclosed in the drawings and specification, and then more particularly pointed out in the appended claims.

In the drawings,

Figure 1 is a detail front elevation of a temperature indicating device constructed according to an embodiment of this invention,

Figure 2 is a plan View of the device,

Figure 3 is a vertical section through the device, showing the device in mounted position within the refrigerator,

Figure 4 is a fragmentary sectional view taken on the line 44 of Figure 3,

Figure 5 is a fragmentary sectional view taken on the line 55 of Figure 3,

Figure 6 is a fragmentary sectional view of aconstruction. The refrigerator Ill is formed with an opening H in one Wall I2 thereof, within which a temperature indicating device constructed according to an embodiment of this inventio-n, and generally indicated as M, is adapted.

to be mounted.

The temperature indicating device [4 comprises a housing, having an outer wall l3, an inner wall l5, upper and lower walls l6 and I1, and opposite side walls l8. One of the side walls, designated I804 is removable, being secured by fastening members I9. The housing M has mounted therein a pair of signal elements which, in the present instance are visible elements, indicated as light bulbs and 2|.

lhe front wall I3 is formed with an inwardly recessed portion 22, having a light socket 23 for receiving the base of the light bulb 20. The front wall l3, at its upper portion, is formed with a second inwardly recessed or offset portion 24, having a light socket 25 for receiving the base of the light bulb 2|.

A pair of switches, generally designated as 26 and 21, are disposed within the housing l4 and are connected in circuit with the signal elements 20 and 2|. The switch 26 includes an elongated resilient arm or bar 28 which is fixed, as at 29, to the inner side of the front wall I3. The fastening member 29 also includes a terminal 30 which is connected by means of a conductor 3| to a terminal 32 associated with the light bulb 2D. The terminal 32 has connected thereto an L-shaped center contact engaging member 33 for engaging the center contact of the lower light bulb 2B. The switch 26 also includes a contact 34 on the lower side or the resilient contact bar 28.

The switch 21 includes an elongated contact bar 35, secured as at 36, to the inner side of the front wall l3, and the bar 35 has a contact 31 on the upper side thereof. A terminal 38 is connected with the outer or forward end of the bar 35 and is connected by means of a conductor 39 to a terminal 46 associated with the upper signal member or light bulb 2|. An L-shap-ed contact member 4| is connected with the terminal 40 and engages the center contact of the light bulb 2|.

A contact carrier 42 of U-shaped construction has a lower leg 43 disposed below the contact 34, and the leg 43 has a contact 44 confronting the contact 34. The carrier 42 also includes an upper leg 45, having a contact 46 confronting the contact 31 of the upper bar 35. The two contacts 44 and 36 are adapted duringnormal operation of the refrigerator, when the temperature within the refrigerator is within a predetermined range,

3 to be disposed out of engagement with the contacts 34 and 31 so that the light bulb or signal elements 2:) and 2| will not be energized,

The carrier 42 is adapted to be vertically moved, according to the variations in the temperature within the refrigerator, by means of a thermostatic member, generally designated as 41. The thermostatic member ll includes a housing 58, formed with a pair of flanges 49 engaging in grooves 50 formed in transversely extending supporting bars which are fixed to the side wall 58 of the housing. The thermostat housing 48 has mounted therei a bellows type member 52 which has extending downwardly therefrom stem '53 which slidably engages through the lower wall 5 2- of the housing 58. The contact 16 is fixed to the lower end of the stem or shank 53. The bellows 52 has connected with the upper side thereof an elongated tube 55 which extends upwardly through the top wall i6, and the tube 55 terminates above the top wall is in a spiral coil The tube and the coil are adapted to be filled with expansible and contractiole gas which will also fill bellows Upon expansion of the gas in the tube 55 and the coil and in the bellows the shank '53 to which the carrier 4-2 is fixed securely will move downwardly so that the upper contact 45 will engage contact 31' of switch 2? and thereby close the electric circuit to the signal element or upper light bulb 2 l.

When the temperature drops below a predeterdegree, the contraction of the gas in the tube the coil and the bellows 52 will cause shank to more upwardly, carrying therewith contact carrier 32 so that lower contact 34 will engage contact At this time an electric circuit wi be closed to the lower signal element or light bulb 22.

In the present instance a battery B is used as a source of electric curr nt supply, and is mounted l. him the housing id. The battery B has a lower contact 5? engaged with a resilient contact connected to a terminal 59. The terminal 59 is connected by means of a conductor E9 to the socket and is also connected by means of a conductor 5! to the socket The center terminal of the batter- *5 has a resilient contact 83 therewith, which is connected to a ter- The terminal is connected by means otor :35 to the thermostat housing 18 s, with the contacts G5 and 4S and the carrier a one common side for the two switches and 2?.

In order to provide a means whereby the closing of switches 25 and 2'5 may be adjusted, I have provided a cam-shaped adjusting member which is secured to a screw shaft 51. l'fhe shaft 6': is threaded through a nut 68, carried by the front wall and a knob 6s is fixed to the outer end of the screw shaft (-2! and is formed with e. pointer l6 swingable across a graduated dial or scale ll carried by the front wall 13,

The upper switch 2! may be adjusted by means adjusting member l2 which is fixed to ried by the front wall l3. A knob 25 is fixed to the outer end of the screw shaft l3 and is provided with a pointer 18 swingable over a dial or scale T on the front wall [3.

Referring now to Figure 6, there is disclosed a slightly modified form or" this invention. As disclosed in Figure 6, the signal elements may be positioned remote from the refrigerator. The signal elements 22a and 2 la are mounted on a panel 13a, at a point remote from the refrigerator. The sockets 23a and 25a of the signal elements are connected together by a common conductor E8. The center contact of the signal member 20a has engaged therewith an L-shaped contact member 33a which is connected to a terminal 32c, and the latter is connected by means of a conductor 3m to the adjustable contact bar 28.

The center contact of the signal member 23a has engaged therewith an L-shaped contact member 4! a which is connected to a terminal 45a, and the latter is connected by means of a. conductor 39a to the contact bar 35. The common conductor T8 is connected by means of a conductor 13 to the conductor 60 which is shown in Figure 3. In other respects the details of construction shown in Figure 3 will be the same for the structure shown in Figure 6.

In the use and operation of this invention, one wall of the refrigerator if: is formed with an opening I l, within which the housing 14 is mounted, so that the temperature of the air within the refrigerator will contact with the thermostat When the gas in the thermostat expands under rise of temperature in the refrigerator, the carrier 42 will be lowered so that contact All will engage contact 3? and close the circuit to the signal member 2!. This signal member may be constructed in the form of a red light bulb.

The user of this device will thereupon be able to determine from glance at the signal members, the approximate temperature of the air within the refrigerator, and can regulate the operation of the refrigerator accordingly.

Where the temperature of the refrigerator normal, carrier 42 will be disposed in a neutral position with the contacts of the carr p :ed from contacts 34 and 31 so that the signal in bers 2| and 20 will not be energized. In the event the temperature of the air in the refrigerator should drop below a predetermined degree, the bellows 52 will contract, thereby raising the car rier 42 and causing contact 44 to engage contact 34. Switch 26 will then be closed and the cir-- cuit will be closed to the green light signal bulb When signal 20 is energized, the user will know that while the temperature within the refrigerator is less than the desired temperature, the ten1- perature will not be such as to cause spoilage oi the food in the refrigerator. Through the adjustment of the cam members 66 and 12, the closing of the switches 26 and 27 may be varied so as to provide for operation of the signal elements within a predetermined minimum and maximum range.

I do not mean to confine myself to the exact details of construction herein disclosed, but claim all variations falling within the purview of the appended claim.

What I claim is:

Temperature responsive switch means comprising a housing, a pair of switches in said housing each adapted to energize an electrical circuit, said pair of switches including a U-shaped contact carrier confronting contacts carried by the parallel legs of said carrier, a pair of elongated resilient bars fixed at one end thereof relative to said housing and extending between said legs of said carrier, contacts carried by said bars confronting the contacts on said legs, a temperature responsive element carried by said housing, a thermostatic operator operatively connected to said element and including a movable member connected to said carrier for moving the latter 2,526,679 5 6 upon variation of the temperature to effect en- REFERENCES CITED gagement of one of the contacts on said carrier Th f n f with the contact on one of said resilient bars when file i g gg igf. erences are of record m the the temperature rises or falls a predetermined degree, and a rotatable cam member carried by said 5 UNITED STATES PATENTS housing and engaging each of said bars for adj ust- Number Name D t ing the latter whereby said contacts Wi l en 934,754 Porter Sept. 21, 1909 at selected predetermined temperatures for ener- 1 7 0 Whjttington 13, 1923 gizing the related electrical circuit. 2,043,3 0 Townsend June 9, 193 10 2,092,085 Riley Sept. '7, 1937 ALVA TYREE MCCARY' 2,115,027 Leonard Apr, 26, 1933 

